Researchers at the Institute for Neurosciences, a joint centre of the Spanish National Research Council (CSIC) and the Miguel Hernández University (UMH) of Elche, have identified the mechanism linking a mutation in the Shank3 gene with alterations in social behaviour. The team’s findings, published in the journal Nature Communications, are said to provide the first detailed explanation of how a genetic mutation linked to autism leads to problems in social interaction. Until now, the Shank3 gene had been associated with autism, but the biological mechanism underlying this connection remained unclear. The study also shows that vasopressin acts in the lateral septum through two different receptors, each responsible for a specific aspect of behaviour: receptor AVPR1a controls sociability, while receptor AVPR1b regulates social aggression. The goal is to design therapies that improve social deficits in people with autism without inducing side effects related to aggression.